cls_cgroup: get sk_classid only from full sockets
skb->sk could point to timewait or request socket which has no sk_classid.
Detected as "BUG: KASAN: slab-out-of-bounds in cls_cgroup_classify".
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index c0a92e2..74c9693 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -17,6 +17,7 @@
#include <linux/hardirq.h>
#include <linux/rcupdate.h>
#include <net/sock.h>
+#include <net/inet_sock.h>
#ifdef CONFIG_CGROUP_NET_CLASSID
struct cgroup_cls_state {
@@ -63,11 +64,13 @@
* softirqs always disables bh.
*/
if (in_serving_softirq()) {
+ struct sock *sk = skb_to_full_sk(skb);
+
/* If there is an sock_cgroup_classid we'll use that. */
- if (!skb->sk)
+ if (!sk || !sk_fullsock(sk))
return 0;
- classid = sock_cgroup_classid(&skb->sk->sk_cgrp_data);
+ classid = sock_cgroup_classid(&sk->sk_cgrp_data);
}
return classid;